<?php

require_once 'HTMLPurifier/Filter.php';

class HTMLPurifier_Filter_YouTube extends HTMLPurifier_Filter
{
	
	var $name = 'YouTube preservation';
	
	function preFilter($html, $config, &$context) {
		$pre_regex = '#<object[^>]+>.+?'.
			'http://www.youtube.com/v/([A-Za-z0-9\-_]+).+?</object>#s';
		$pre_replace = '<span class="youtube-embed">\1</span>';
		return preg_replace($pre_regex, $pre_replace, $html);
	}
	
	function postFilter($html, $config, &$context) {
		$post_regex = '#<span class="youtube-embed">([A-Za-z0-9\-_]+)</span>#';
		$post_replace = '<object width="425" height="350" '.
			'data="http://www.youtube.com/v/\1">'.
			'<param name="movie" value="http://www.youtube.com/v/\1"></param>'.
			'<param name="wmode" value="transparent"></param>'.
			'<!--[if IE]>'.
			'<embed src="http://www.youtube.com/v/\1"'.
			'type="application/x-shockwave-flash"'.
			'wmode="transparent" width="425" height="350" />'.
			'<![endif]-->'.
			'</object>';
		return preg_replace($post_regex, $post_replace, $html);
	}
	
}

